This is called as dyspepsia . May be functional or due to diseases . if this is first experince , changing food habits & specifics medicines helps u or otherwise u need investigations.

Hello....... Nausea, epigastric pain, vomiting are symptoms of gastritis... You didn't mention about medicine, Take curdrice ,drink plenty of water , have frequent small meals instead of large regular meals.Sleep 2-3 hours after having dinner . Avoid spicy, hot ,high protein containing foods like fish .Take dal rice , butter milk